This three year research project will analyze teenage social influence processes as they relate to the adoption and maintenance of smoking and will develop and evaluate a smoking prevention program based on the analysis. Although smoking is the target of these studies, our understanding of the social influence processes involved in the adoption of teenage smoking could have important implications for affecting other health risk behaviors. Smoking is a widespread health risk behavior that begins most often in teenage years and is usually continued throughout life. Our ability to understand and arrest this process could have important social implications. Indeed, smoking prevention may be a more efficient use of resources than focusing our attention on smoking cessation for habitual smokers. The studies are derived from a social learning analysis of social influence processes. Social learning theory suggests that a youth's initial smoking is modeled and reinforced by peers and his refusals are punished. Teaching teenagers new ways to refuse cigarettes and to support others' refusals might alter the peer social influences that affect initial smoking. Teaching teenagers to contract with peers or parents for nonsmoking establishes additional contingencies that are countervailing to the usual peer contingencies for smoking. Phase 1 of the project will develop and evaluate peer led programs for teaching teenagers refusal and refusal support behaviors and engaging teeangers in contingency contracts with their peers or parents for not smoking. In Phase 2 the effectiveness of the Social Behavior Program and the Social Behavior plus Contracting Program will be evaluated. The knowledge gained in the first phase will be systematically applied toward the development of treatment packages which will be compared with no treatment in a study with 780 ninth grade students.